CH 82 Drugs for PUD Flashcards
What are the goals of drug therapy for peptic ulcer disease (PUD)?
- Relieve pain and discomfort
- Promote ulcer healing
- Prevent ulcer recurrence
- Eliminate the cause (e.g., H. pylori)
- Reduce gastric acid secretion
Why are two or more antibiotics used in PUD treatment?
- To improve eradication rates of H. pylori
- To prevent antibiotic resistance
- Combination therapy is more effective than monotherapy
Drug: Clarithromycin (Biaxin)
Class: Antibiotic (Macrolide)
MOA: Suppresses H. pylori growth by inhibiting protein synthesis.
Note: Can cause taste distortion; resistance rates are rising.
Drug: amoxicillin
Class: Antibiotic (Penicillin)
MOA: Kills bacteria (H. pylori) by disrupting the cell wall.
Note: Activity is highest at neutral pH; enhanced with acid reducers.
Drug: Bismuth Compounds
Class: Antibiotic / Mucosal Protectant
MOA: Disrupts H. pylori cell wall, inhibits urease activity, prevents adherence.
Note: Can cause harmless black coloration of tongue and stool.
Drug: tetracycline
Class: Antibiotic (Tetracycline)
MOA: Inhibits bacterial protein synthesis.
Note: Can stain developing teeth; avoid in pregnancy and young children.
Drug: metronidazole (Flagyl)
Class: Antibiotic (Nitroimidazole)
MOA: Effective against sensitive H. pylori strains (MOA not specified).
Note: Avoid alcohol due to risk of disulfiram-like reaction. >40% resistance.
What is the difference between an H2 receptor antagonist and an antihistamine?
H2 receptor antagonists block histamine in the stomach lining to reduce acid production
Antihistamines (H1 blockers) treat allergic symptoms by blocking histamine in the respiratory tract and other tissues
Drug: cimetidine (Tagamet)
Class: H2-Receptor Antagonist
MOA: Suppresses gastric acid secretion by blocking H2 receptors.
Note: Has antiandrogenic effects and many drug interactions.
Drug: ranitidine (Zantac)
Class: H2-Receptor Antagonist
MOA: Suppresses gastric acid secretion by blocking H2 receptors.
Note: More potent and fewer interactions than Cimetidine.
What is the role of H2 blockers in PUD management?
Reduce gastric acid secretion by blocking histamine-2 (H2) receptors on parietal cells
Help relieve symptoms and promote ulcer healing
Drug: famotidine (Pepcid)
Class: H2-Receptor Antagonist
MOA: Suppresses gastric acid secretion by blocking H2 receptors.
What is the role of proton pump inhibitors (PPIs) in PUD management?
- PPIs irreversibly block the proton pump (H⁺/K⁺-ATPase) in parietal cells
- Most potent suppressors of gastric acid secretion
- Used for short-term and maintenance therapy, especially in severe or NSAID-related ulcers
More effective than H2 blockers and antacids for healing ulcers and suppressing acid
Drug: omeprazole (Prilosec)
Class: Proton Pump Inhibitor (PPI)
MOA: Inhibits gastric acid secretion by suppressing the H+/K+ ATPase enzyme.
Note: Most effective class for acid suppression; ICU ulcer prophylaxis use.
What are the roles of sucralfate and misoprostol in PUD management?
Sucralfate (Carafate): forms a protective barrier over ulcers; not acid-suppressing
Misoprostol (Cytotec): prostaglandin analog that protects gastric mucosa and decreases acid; especially used to prevent NSAID-induced ulcers
Drug: sucralfate (Carafate)
Class: Mucosal Protectant
MOA: Creates a protective barrier over ulcers for up to 6 hours.
Note: Side effect: constipation. Interacts with antacids.
Drug: misoprostol (Cytotec)
Class: Prostaglandin Analog
MOA: Enhances mucosal defense, suppresses acid secretion.
Note: Used to prevent NSAID-induced ulcers.
Contraindicated in pregnancy.
Drug: Magnesium hydroxide (Milk of Magnesia)
Class: Antacid; osmotic laxative
MOA: Neutralizes stomach acid and draws water into the intestines.
Note: Causes diarrhea; often combined with aluminum hydroxide.
Use w/ caution in renal failure
Drug: Aluminum hydroxide
Class: Antacid
MOA: Neutralizes gastric acid.
Note: Causes constipation; often combined with magnesium to balance effects.
Drug: Calcium carbonate (Tums)
Class: Antacid
MOA: Neutralizes gastric acid.
Note: May cause belching and constipation; risk of acid rebound.
Drug: Sodium bicarbonate (Alka-Seltzer)
Class: Antacid
MOA: Rapidly neutralizes stomach acid.
Note: Not suitable for long-term use due to high sodium content; may cause alkalosis.
